Jurassic salamanders with stomach contents found from Inner Mongolia 6 February 2012 specimens recovered, two specimens of Jeholotriton paradoxus (IVPP V14195, IVPP V18083) with conchostracans preserved in stomachs and nine specimens of Chunerpeton tianyiensis (IVPP V18084 - V18092) with corixids preserved in stomachs have been recognized. Researchers observed there are more than 50 conchostracan carapaces in the abdominal region of juvenile Jeholotriton paradoxus (IVPP V14195), which is about 96 mm in length (from the snout to Fig.1 Jeholotriton paradoxus with conchostracans the tip of the tail). The carapace valves identified as preserved as stomach contents. (a) IVPP V14195B; (b) stomach contents are clustered, overlapping IVPP V18083; (c) enlargement of conchostracans in the heavily, and the margin of the conchostracan abdomen of IVPP V14195B. Scale bars: 10 mm. cluster below the vertebral column within the outline of the abdominal region. The carapaces are relatively small, whereas the conchostracans from Daohugou bed are normally dispersed and have a Paleontologists from Chinese Academy of large size range. This suggests selection of prey Sciences reported two Jurassic salamanders with size by the predator. The conchostracans in the stomach contents from Daohugou, Ningcheng abdominal area appear relatively circular, in County, Inner Mongolia, China, as reported in contrast to the more or less oval carapace valves Chinese Science Bulletin online January 2012 outside the salamander's body. Their rounded (Vol.57, No.1). This is the first report of well- shape could be a result of softening of the chitinous established fossil caudates with food in their valves during digestion. A proportionally large stomachs, and these specimens provide important number of the conchostracans in the abdominal evidence supporting hypotheses about ecological region are preserved dorsally with the two valves interactions in the Jurassic ecosystem of open, suggesting the adductor muscle had been Daohugou. digested before burial. No tooth marks are present on the surfaces of the conchostracan valves in the The Jurassic site at Daohugou, Ningcheng County, abdomen, implying that they must have been Inner Mongolia, China, has yielded an important swallowed whole rather than bitten. The assemblage of fossil plants, invertebrates (e.g. conchostracans in the abdominal region appear to anostracans, conchostracans, spiders, occupy nearly the entire body cavity, probably harvestmen, and insects), and vertebrates (e.g. because the carapaces broke the gut and entered salamanders, lizards, feathered dinosaurs, the coelom as they were pressed during burial. All pterosaurs, and mammals). The caudates from this the conchostracans on the slabs can be identified locality are dominanted by neotenic species, to be a single species Euestheria luanpingensis. Jeholotriton paradoxus, and Chunerpeton tianyiensis, as well as the metamorphosed Liaoxitriton daohugouensis, and many of them are well-preserved articulated skeletons, even retaining soft tissue impressions (e.g. eyes, gills, skin, tail fins). Among more than 600 caudate 1 / 3 of these corixids are sometimes disarticulated, indicating that the joints was digested in the stomach. In addition, there are no tooth marks on the eaten corixids, indicating that they were probably swallowed whole. "Chunerpeton could eat more than one individual corixid in a meal, as shown in Figure 2(b), and sometimes took many more as indicated by IVPP V18089, in which as many as five corixids can be observed in the abdominal region", said the study coauthor HUANG Diying, Nanjing Institute of Geology and Palaeontology. "Living newts tend to change their diet as they grow. Younger juveniles generally feed on very Fig.2 Chunerpeton tianyiensis with corixids preserved as small prey, such as protozoans and vegetation stomach contents. (a) IVPP V18085 with one corixid in its fragments. As growth proceeds, they begin to belly; (b) IVPP V18086 with two corixids shown by forage on moderately sized invertebrates, such as arrows; (c) enlarged view of the corixid in the belly of corixids and minute crustaceans, and then switch to IVPP V18085; (d) IVPP V18087 preserved laterally with even larger prey that may include small juvenile one corixid in its belly showing its hind leg. Scale bars: 10 conspecies. As described above, juvenile mm. Jeholotriton preyed on only small conchostracans about 2 mm long, and juvenile Chunerpeton ate only adult corixids 5 - 6 mm long. The adults of each salamander taxon presumably took larger "It is not surprising to discover that a Jurassic prey, such as fishes or frogs, as do their living salamander ate conchostracans. Werneburg relatives. However, no adult specimens of described a specimen of the temnospondyl Jeholotriton or Chunerpeton have been found with Apateon with a skull length of 10 mm, whose stomach contents preserved, so the adult diet of stomach contents included small conchostracans. these taxa remains uncertain", said Dr. WANG Apateon is probably close to the ancestral Yuan, coauthor of the study and professor of the salamander condition. Extant caudates (e.g. IVPP, "Jurassic caudates with gut contents can Ambystoma cingulatum; Salamandra salamandra) also provide insights into the feeding behaviors and have also been reported as preying on foraging environments of these ancient, tailed conchostracans", said the first study author DONG amphibians." Liping, a paleontologist graduate student of Institute of Vertebrate Paleontology and Paleoanthropology This work was supported by the National Natural (IVPP). Science Foundation of China and the Knowledge Innovation Program of the Chinese Academy of Nine specimens with stomach contents can be Sciences. referred to juvenile Chunerpeton tianyiensis, ranging from 30 to 62 mm in length (from the snout to the tip of the tail), and the contained corixid Provided by Institute of Vertebrae Paleontology Yanliaocorixa chinensis, is a common insect of the and Paleoanthropology Yanliao entomofauna. The corixids found in the stomachs of these salamanders are 5 - 6 mm in length, and exclusively represent adults or last larval instars, suggesting size-based selective feeding of the live predator. The head or fore wings 2 / 3 APA citation: Jurassic salamanders with stomach contents found from Inner Mongolia (2012, February 6) retrieved 27 September 2021 from https://phys.org/news/2012-02-jurassic-salamanders-stomach- contents-mongolia.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. 3 / 3 Powered by TCPDF (www.tcpdf.org).